The river otter is part of a family of long-bodied, semi-aquatic members of the weasel family. They make up 11 or 12 species found on all continents except Australia and Antarctica, including the North American otter. Otters have broad snouts, small ears, short legs with fully webbed feet, and a thick and tapering tail. Their underfur is dense and short, brownish or grayish, and has an overlay of darker and coarser hair. Male river otters may reach body length of three feet (1 m), with up to a 19 -inch (50 cm) tail. They may weigh up to 30 pounds (14 kg). They feed on amphibians, crustaceans, fish, and turtles, and sometimes birds and small land mammals.